HD 285507b: an eccentric hot Jupiter in the Hyades open cluster
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We report the discovery of the first hot Jupiter in the Hyades open cluster. HD 285507b orbits a V = 10.47 K4.5V dwarf (M * = 0.734 M ☉; R * = 0.656 R ☉) in a slightly eccentric () orbit with a period of days. The induced stellar radial velocity corresponds to a minimum companion mass of M Psin i = 0.917 ± 0.033 M Jup.
Line bisector spans and stellar activity measures show no correlation
with orbital phase, and the radial velocity amplitude is independent of
wavelength, supporting the conclusion that the variations are caused by a
planetary companion. Follow-up photometry indicates with high
confidence that the planet does not transit. HD 285507b joins a small
but growing list of planets in open clusters, and its existence lends
support to a planet formation scenario in which a high stellar space
density does not inhibit giant planet formation and migration. We
calculate the circularization timescale for HD 285507b to be larger than
the age of the Hyades, which may indicate that this planet's non-zero
eccentricity is the result of migration via interactions with a third
body. We also demonstrate a significant difference between the
eccentricity distributions of hot Jupiters that have had time to tidally
circularize and those that have not, which we interpret as evidence
against Type II migration in the final stages of hot Jupiter formation.
Finally, the dependence of the circularization timescale on the
planetary tidal quality factor, Q P, allows us to constrain the average value for hot Jupiters to be .
Original language | English |
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Article number | 27 |
Journal | Astrophysical Journal |
Volume | 787 |
Issue number | 1 |
Number of pages | 10 |
ISSN | 0004-637X |
DOIs | |
Publication status | Published - 2014 |
ID: 140018117